The join()
method joins all elements of an array into a string.
var a = ['Wind', 'Rain', 'Fire']; a.join(); // 'Wind,Rain,Fire' a.join('-'); // 'Wind-Rain-Fire'
Syntax
arr.join() arr.join(separator)
Parameters
separator
Optional- Specifies a string to separate each element of the array. The separator is converted to a string if necessary. If omitted, the array elements are separated with a comma. If
separator
is an empty string, all elements are joined without any characters in between them. Defaults to ",".
Return value
A string with all array elements joined.
Description
The string conversions of all array elements are joined into one string. If an element is undefined
or null
, it is converted to the empty string.
Examples
Joining an array four different ways
The following example creates an array, a
, with three elements, then joins the array four times: using the default separator, then a comma and a space, then a plus and an empty string.
var a = ['Wind', 'Rain', 'Fire']; a.join(); // 'Wind,Rain,Fire' a.join(', '); // 'Wind, Rain, Fire' a.join(' + '); // 'Wind + Rain + Fire' a.join(''); // 'WindRainFire'
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 1st Edition (ECMA-262) | Standard | Initial definition. Implemented in JavaScript 1.1. |
ECMAScript 5.1 (ECMA-262) The definition of 'Array.prototype.join' in that specification. |
Standard | |
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Array.prototype.join' in that specification. |
Standard | |
ECMAScript 2017 Draft (ECMA-262) The definition of 'Array.prototype.join' in that specification. |
Draft |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | 1.0 | 1.0 (1.7 or earlier) | 5.5 | (Yes) | (Yes) |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
See also
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Last updated by:
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